The thing is, it really wasn't that long ago that these weren't the ideals for a baseball stadium. Instead of flashy modernism, all a team wanted was red brick, exposed steel, and needlessly quirky outfield dimensions. Now, those retro ballparks just seem...old. Is space-age Marlins Park the last shiny nail in the coffin of the retro-classic stadiums? That's the argument made by The Atlantic Cities, and it's hard to disagree that era of the retro ballpark is dead, consigned to a past not even tinted by nostalgia.

Oriole Park at Camden Yards somehow turns 20 this week, and there are sports fans reading this who weren't born when it opened to great fanfare and sold-out crowds for years and years. It's hard to believe in a post-Wire world that a simple baseball stadium was held up as the symbol of a renewed and revitalized Baltimore, but there it was. The Orioles started winning, and the fans kept coming, and Camden Yards became a destination unlike any ballpark since the Fenway-Wrigley-Yankee trinity.

Now it's just another ballpark. The 10th-oldest in baseball, in fact. Jake Arrieta is the opening day starter and the O's have reverted to being terrible and you can walk up to the ticket window and buy $10 seats most every night. Camden Yards hasn't lost its charm, it's lost its uniqueness. In the wake of Camden's success, ballpark designers HOK (now Populous) went on a building spree. Texas and Colorado and Atlanta all got their retro parks, as did San Francisco and Pittsburgh and Philadelphia.

"The heterogeneity has come to seem altogether homogenous," wrote Metropolis Magazine once the frenzy had subsided. Soon teams were looking to stand out from the crowd of standouts: Yankee Stadium opted for Ancient-Rome-cum-Las Vegas grandeur, while Miller Park is all functional airplane hangar.

This is how it happens; tastes change. Nothing is taken away from PNC Park because retro is out. But while there's only a short-term gain from building a ballpark ahead of the curve, there is shame in being the last. The legend goes that the White Sox were offered by HOK the chance to have the first retro park, but turned it down in favor of the blandness of New Comiskey. "It had everything but a soul," Mike Veeck said. U.S. Cellular has undergone extensive renovations to bring it up to date with parks like Camden Yards, which opened just one year later.

This time around the Mets are the odd team out. Citi Field opened in 2009, a full five years after the last purely retro park had been built. The Mets were criticized at the time for going retro by cannibalizing the history of a completely separate franchise, so maybe they deserve the blight of an already-outdated stadium that they can't leave until 2049.

It would have been silly for the Marlins to go retro—there's no history to speak of with South Florida baseball, so an old-school park would have felt more out of place than a garish animatronic sculpto-pictorama. The next few ballparks to come down the line (there won't be a rolling wave, as so many teams already have their old-new brick-and-steel palaces) will be monuments to individualism. Jeffrey Loria's concept of what entails "art," for example, or the dormant St. Pete plan that would look like no ballpark built in this century or last. Because excess is the new excess, and the chance of spectacular failure beats the boringly competent every time.